entc/gen: revet the new format for enums (#581)

Some acronyms don't exist in entc, and we define them as uppercase to control the Go constant name

entc/gen/template/meta.tmpl

@@ -115,7 +115,7 @@ const (
 		// {{ $name }} is a validator for the "{{ $receiver }}" field enum values. It is called by the builders before save.
 		func {{ $name }}({{ $receiver }} {{ $enum }}) error {
 			switch {{ $receiver }} {
-				case {{ range $i, $e := $f.Enums }}{{ if ne $i 0 }},{{ end }}{{ $f.StructField }}{{ lower $e | pascal }}{{ end }}:
+				case {{ range $i, $e := $f.Enums }}{{ if ne $i 0 }},{{ end }}{{ $f.StructField }}{{ pascal $e }}{{ end }}:
 					return nil
 				default:
 					return fmt.Errorf("{{ $.Package }}: invalid enum value for {{ $f.Name }} field: %q", {{ $receiver }})

entc/gen/type.go

@@ -615,7 +615,7 @@ func (f Field) Enums() []string {
 
 // EnumName returns the constant name of the enum value.
 func (f Field) EnumName(enum string) string {
-	return pascal(f.Name) + pascal(strings.ToLower(enum))
+	return pascal(f.Name) + pascal(enum)
 }
 
 // Validator returns the validator name.

entc/gen/type_test.go

@@ -136,6 +136,23 @@ func TestType_Receiver(t *testing.T) {
 	}
 }
 
+func TestField_EnumName(t *testing.T) {
+	tests := []struct {
+		name string
+		enum string
+	}{
+		{"GIF", "TypeGIF"},
+		{"SVG", "TypeSVG"},
+		{"PNG", "TypePNG"},
+		{"MP4", "TypeMP4"},
+		{"unknown", "TypeUnknown"},
+		{"user_data", "TypeUserData"},
+	}
+	for _, tt := range tests {
+		require.Equal(t, tt.enum, Field{Name: "Type"}.EnumName(tt.name))
+	}
+}
+
 func TestType_WithRuntimeMixin(t *testing.T) {
 	position := &load.Position{MixedIn: true}
 	typ := &Type{